Improvement in dental brackets



W. D. EWART. Dental Bracket.

No. 201,876. Pt ented April 2, I878.

a INVENT, 012: JZZeJ-Z: if: 16} f "A d z It PETERS, FHOTO-LITHOGRAFHER, WASHINGTON, Dv C teeth of patients.

UNITED STATES PATENT- OFF oE.

WILLIAM D. EWART, on CHICAGO,

ILLINOIS, Assienon To" ABNER B.

THOMAS AND BARTON SEWELI), OF SAME PLACE.-

IMPROVEMENT IN DjENTAL BRACKETS.

Specification forming part of Letters Patent No. 2bl,s7 6 ,"datefi April 2,'1 878; application filed October 22, 1877. p 4

To all whom it may concern: I

Be it known thatI, WILLIAM D. EWART, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Dental Brackets, of which the following is a full, clear, and exact description, which will enable others skilled in the art to which my invention appertains to make and use the said improvements, refer ence being bad to the accompanying drawing forming a part hereof, and in which- Figure 1 is a top or plan view of a dental bracket embodying my invention; Fig. 2, a side elevation thereof, shown partly in section; Fig. 3, a detail in perspective, showing the joint which connects the sliding rod to the links; Fig. 4, a like representation, showing the construction and arrangement of the parts employed for clamping and releasing the slidin g rod; and Fig. 5, a vertical central section of the same parts, and of the part to which they are applied.

Like letters of reference indicate like parts.

My invention relatesto a class of brackets used'by dentists, and serving as 'an accessible place in which they may arrange their toolsand implements while operating upon the It is then necessary for the operator to change his position frequently, and thesebrackets have therefore been made adj ustable. My invention relates to the means employed for rendering them easily adjustable;

and consists of certain novel features of construction, substantially as hereinafter set forth, which I have adopted for that purpose.

In the drawing, A represents a small wallplate, which may be fastened to the wall or other convenient place'in any suitable manner. B is a vertical post or stud set to turn freely in the bearings 00 a, projecting horizontally from the plate A. O is a tubular arm, knuckle-jointed, or otherwise so connected to the upper part of the post B that the arm may be swung vertically on its joint. D is an arm or lever, terminating vertically at its upper end, and there so jointed to the outer end of the arm 0 as to be capable of being swung in the direction in which the latter arm extends. E is a slide-bar or connecting-rod arranged within the arm O. F and F are links,

preferably knuckle-jointed to the plugs G and G, respectively, which arerun upon the ends 7 of the rod E, and fitted to play nicely within the arm 0 during the sliding movement of the rod to which they are applied. The outer or] lower ends of the links F and F are jointed to the post B and to the lever D, respectively, at

points below the plugs G and G, as'repre sented in Fig. 2. The rod 0 is slotted at a" a,

to admit of the movement of the links F and F; H is a hollow post or stud turning freely on a pin projecting vertically from the upper end of theleverD. II are parallel armsproject ing horizontally from the postH. J is a rotary 7 table, mounted ona center-pinpassing freelybe: j tween the arms I I, and screw-threaded on its e e are washer'slor clamping-blocks lower end. on'the center-pin. These blocks are arranged one above and the other below the rods I I, and 1 1 should be grooved or fitted to ride nicely there;

on when the table is moved back and forth, it 4 being understood that a nut, 'e, on the lower end of the center-pin may belo'ose'ned to admit of this movement, and tightened to retain the table in any desired position on thjearms' I I. The upper clamp 0 should be rigidly attached to the center-pin, so that the rotation of the table will not be prevented whenthe nut e is tightened. The'table may be mounted upon only one arm or rod; but I deem it preferable to employ two to prevent the table from being tilted or rocked on its support. K is a small cam-lever,.the cam end of which enters the arm 0. K is a loop or lug pivoted to the lever K. The rod E passes through the loop K, and is in contact with the cam. A small pin, it, depends from the long arm of the lever K and enters the arm 0. n is an open spiral spring exerting an upward pressure against the lever K, and holding the cam against the rod 0. The loop K may be tied to the rod 0 by means of a screw or pin, a.

It will be perceived from the foregoing description that the table J is not only rotary on its center-pin, but that it is also adjustable horizontally on the arms I I, and may be revolved horizontally about the post H. The re volving and sliding movement maybe accom the same manner, it being understood that the nut must be loosened in order to adjust the table on its supporting-arms, and that the not should be tightened after the table is adjusted. It may be sufficient, ordinarily, if the nut is made only tight enough to prevent a too free movement of the table on its supports, and to admit of an adjustment without requiring a further loosening of the nut. In other words, a friction-clamp will serve the purpose of the nut and washers.

The table may also be elevated and revolved about the post B as a center while the hand is on the nut for any of the purposes above set forth; or the nut may be grasped for that or any other special purpose. It will be perceived that any or all of these movements may be made by using only one hand.

The table will be held at any elevation at which it may be placed, for the reason that its tendency to descend, as well as the action of the spring n, causes the cam to bite the rod E, and the latter is thus crowded against the tied loop K with sufiicient force to prevent the rod from sliding forward in the arm C, it being evidentthat this rod must so move in order to allow the arm to descend, and that the rod must move either forward or backward in, the arm whenever the inclination of the latter with respect to the post B is changed, the rod and arm both occupying the same, or nearly the same, horizontal plane, and both being tied to the post B at difierent elevations. When, however, the forward end of thearm G is elevated, the rod E will move' freely between the cam and the loop K, the friction of the 'rod against the cam tending to raise and loosen the latter. In order, therefore, to lower the table, the outer end of the lever K should bedepressed, so 'as to free the rod E with certainty; The spring n will throw the cam against the rod as soon as the long arm of the lever is released. Other similar means for clamping the rod may be employed.

It will also be evident that the table will always be retained in a horizontal position V during all of these movements, owing to the connection of the link F to the pivoted lever D, in the manner described.

It is also evident that the arm 0 need not be hollow,- although I deem the tubular form to be the best, as it shields the rod E, and renders the bracket attractive in appearance. 7

The arm C may consist of a solid bar or rod,

in which case' it may be encircled by loops or lugs employed to hold the rod E in the same relative position it now occupies. The arm 0 may also be skeleton in form, and a drawer may be applied to the table. Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

-1. A dental bracket wherein the tool-table is automatically retained in a horizontal posiclamped toa horizontal arm by means of the finger-nut e, the saidarm mounted freely on a vertical pin, for the purpose of thereby admitting of the adjustment of the table on its arm, and offthe adjustment of the arm onits pin or supporting-post, by one act or operation, substantially as specified.

3. The combination of the wall-plate A, the

pivoted vertical post B, arm 0, jointed to the said post,'lever D, jointed to the arm A, and

carrying the table-supporting arm, the sliding rod E, links F and F, and the lever K, sub stantially as and for the purposes specified. WILLIAM D. EWART. Witnesses;

Bonus 0. HALL, JOHN R. DALEY. 

